WASHINGTON — As a partner in a law and lobbying firm, Rudy Giuliani has profited from his firm's work representing corporate clients before nearly every Cabinet department, exposing himself to a wide range of potential ethical entanglements.

If Giuliani became president, his administration would be on the receiving end of regulatory requests, contract bids and policy proposals by the same clients of his Houston firm, Bracewell & Giuliani, that have contributed toward his personal net worth of millions of dollars.

Although the Republican has so far declined to identify all the companies with which Bracewell and his other firms have done business over the past five years, The Associated Press identified more than 175 as part of an expansive review of lobbying records, court filings and securities reports.

Giuliani's law and lobbying clients have included Saudi Arabia, Rupert Murdoch's News Corp., and chewing tobacco maker UST Inc.

Traditional procedures for government officials to prevent ethical conflicts — avoiding issues directly involving their former employer — would be unavailable for a commander in chief. It is unheard of for a president, when taking office, to promise to step away from a particular issue.

Bracewell alone has thousands of clients but will name only a few dozen. Since Giuliani became a partner in spring 2005, it has reported lobbying on various issues with the White House, the vice president's office, Congress and every Cabinet agency except the Department of Veterans Affairs, the AP review found.

Federal conflict-of-interest rules do not apply to the president or vice president, because they are not technically considered government employees. Giuliani isn't registered as a lobbyist for any of the interests on whose behalf his firms have acted, and he has so far declined to describe his work for them.

But appearances matter when it comes to the public's perception of conflicts of interest, and the large number of clients and issues linked to Giuliani's firms could prove a liability.

Giuliani declined to comment.

"It's clear voters are looking for an experienced leader like Mayor Giuliani with a track record of results to tackle the difficult issues currently facing our country," campaign spokeswoman Maria Comella said. She declined to describe Giuliani's work at Bracewell or how he was compensated.

Congress, the Pentagon, Energy and Education departments and the Environmental Protection Agency were among offices most frequently contacted by Bracewell & Giuliani, reports show. Issues ran the gamut: